1. Field of the Invention
The subject of the present invention is a method for setting parameters of a field station equipped with an antenna for exchanging data in a contactless manner through inductive RFID technology with electronic tags, equipped with a signalling unit and equipped with electronic circuits including a memory containing a parameter such as for example a network address. The invention also concerns a system for setting parameters of the field station.
In certain production or handling processes, it is sought to identify the products or moving objects with a view to tracking the management of information related to the said products or moving objects. One known method consists in assigning data to each product or moving object using an electronic tag and in exchanging this information with distributed field stations.
An RFID (Radio Frequency Identification) system is commonly used to identify, via a field station, objects each carrying an electronic identification tag. Within the range of the reader/writer station, the electronic tag exchanges a variety of information with the station, such as for example identification information or information related to the production process taking place.
The field stations communicate with automation equipment (data server on the network) generally in a fieldbus such as MODBUS, FIPIO, etc. In an RFID type identification system, each station has an antenna generating a magnetic field for powering each electronic tag passing within its range and for communicating with the latter according to a predefined communication protocol. The tag is powered by the “carrier” transmitted from the station's antenna. The energy received by the tag's antenna is converted to electrical energy and powers the internal circuits (memory, control circuit, etc.) of said tag in order that the tag executes the programs for which it is designed. This electronic tag stores data, executes commands from the station and transmits requested data to the station. The exchange procedure involves several phases, in particular: transmission of energy as soon as the tag arrives within the range of the field station, the sending of an identification command by the field station, sending a read/write command, writing data or reading data.
Contactless data exchange is achieved through an inductive technology which is based on the use of a medium-frequency electromagnetic signal (carrier) for the contactless transmission of information between stations and electronic tags.
2. Description of the Prior Art
The different field stations are identified in an automation network by distinct addresses. Presently, the addresses of each field station are set via a button or a coding wheel implemented in each station (document EP1324494) or using a terminal that the operator connects to each of the stations in the network.
Document DE 196 01 511 C1 discloses a method for setting parameters of a reader station. This method is executed in a contactless manner between the reader station and a card connected to a personal computer via a serial link. When the card is close to the station, the magnetic field from the station powers the circuits of the card which can send parameter-setting data retrieved on the personal computer to the station. In this method, the parameter-setting operation requires heavy and expensive infrastructure.